Primary alcohol sulfate detergent compositions



United States Patent 3,480,556 PRIMARY ALCOHOL SULFATE DETERGENT COMPOSITIONS William J. De Witt, Burlington, NJ., and Robert C. Taylor, King of Prussia, Pa., assignors to Atlantic Richfield Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Filed Sept. 29 1966, Ser. No. 583,104 Int. Cl. C11d 1/60, 11/42 US. Cl. 252-152 Claims ABSTRACT OF THE DISCLOSURE Detergent compositions having superior washing properties comprise a mixture of straight chain and beta branched chain primary alcohol sulfates.

This invention relates to improved detergent compositions. More particularly, this invention relates to a mixture of straight and 2-alkyl primary alcohol sulfate detergents. In another aspect, it relates to aqueous slurries and solutions of these detergents.

The salts of higher molecular weight straight chain primary alcohol sulfates containing from 16 to carbon atoms are poor detergents in applications where foam heights and foam stability are critical, such as dishwashing. For the same reasons, primary alcohol sulfates which are branched at the second (beta) carbon do not possess the optimum dishwashing properties. It has been found, however, that a mixture of these two primary alcohol sulfates has superior detergent properties when compared to either of the sulfates alone.

Therefore, it is an object of this invention to provide mixtures of straight and beta-branched chain primary alcohol sulfates which have superior detergent properties.

It is a further object of this invention to provide aqueous detergent compositions which have outstanding foam characteristics.

Specifically, the detergent compositions of this invention comprise in parts by weight (1) 100 parts of a detergent comprising (a) from 10 to 90 parts of a straight chain primary alcohol sulfate having the structural formula wherein R is a straight chain alkyl radical containing 14 to 18 carbon atoms and X is a radical selected from the group consisting of Na, K, NH R'R"NH and RR"R'N wherein R'R" and R' are hydroxylated alkyl radicals containing from 1 to 3 carbon atoms and (b) from 90 to 10 parts of a beta-branched chain primary alcohol sulfate having the structural formula wherein the total number of carbon atoms ranges from 12 to 20 and R is a straight chain alkyl radical containing 9 to 17 carbon atoms and R is a straight chain alkyl radical containing 1 to 9 carbon atoms and X is as defined in (a).

with

(2) From 0 to about 10,000 parts water and (3) From 0 to 100 parts of foam builders.

It has been found that when the straight and betabranched chain primary alcohol sulfates are combined in water with the appropriate foam builders the resulting formulation has a better dishwashing ability than the same formulations containing either the straight or betabranched chain primary alcohol sulfates alone.

With reference to (b) above, the beta-branched chain primary alcohol sulfates can contain from 12 to 20 car bon atoms and preferably contains 14 to 18 carbon atoms. R is preferably a methyl or ethyl radical. The branched chain sulfate can be combined with the straight chain sulfate (a) in ratios of from 9:1 to 1:9. Consequently, from 10 to parts by weight of the beta-branched chain primary alcohol sulfate can be combined with from 90 to 10 parts of the straight primary alcohol sulfate. Preferably, the beta-branched chain primary alcohol sulfate is present in an amount ranging from. 20 to 60 parts by Weight per parts of the total detergent ((a)+(b)). The branched chain primary alcohol sulfate can be less than, equal to or greater than the molecular weight of the straight chain primary alcohol sulfate. The sodium salts of each sulfate are preferred.

The mixture of detergents can exist as a dry powder or in an aqueous medium. Preferably, since drying is expensive it is in an aqueous medium. The concentration of detergent in the slurry can vary over a wide range depending upon the application requirements. Whether the aqueous composition is a slurry or a true solution depends upon the concentration and solubility of each of the particular sulfates. For example, the sodium salt of n-hexadecanol sulfate exists only as a slurry at a concentration of 10 percent in water. Similarly, since the solubility of the salt decreases with increasing molecular weight most aqueous compositions containing the n-eicosanol sulfate salt will be slurries rather than solutions. It is normally desirable to prepare aqueous compositions having a detergent concentration ranging from about 1 to about 50 weight percent. Preferably, the detergent concentration ranges from 10 to 40 weight percent.

While an improvement in foam characteristics is obtained merely by combining the straight and branched chain salts in water, the optimum improvement occurs when foam builders are added to this aqueous composition. Foam builders are well-known in the art. Their primary function is to stabilize the foam. Examples of suitable foam builders include but are not limited to fatty alcohols such as lauryl alcohol, fatty m-onoand diethanol amides such as coco-acid diethanol amides, nonionics such as lauryl alcohol ethoxylate or alkylphenol ethoxylate, sulfated nonionic such as lauryl alcohol ethoxy sulfate or alkylphenol ethoxy sulfate, saponins, lecithin fractions obtained from refining sunflower seed oil cellulosic materials such as ethylcellulose, higher aliphatic diols such as hexadecane-1,2-diol, imides of dicarboxylic acids such as 4-octadecene-1,Z-dicarboxylic acid imide and N- alkyliminodiacetic acid, esters of aryl phosphoric acids such as the sodium salt of the methylester of para-tertoctylbenzene phosphoric acid. These builders can be added in functional amounts generally ranging from O to 100 parts per 100 parts detergent. Preferably, the builders are added in amounts ranging from 5 to 60 parts per 100 parts detergent.

The compositions of this invention can be prepared by any suitable method. For example, the detergents can be prepared by reacting a primary alcohol with sulfur trioxide to form the monoester and then neutralizing to the salt. These detergents can then either be dried to a powder or added to water to form a slurry or solution.

Other ingredients which are commonly added to detergent compositions can be added to the compositions of this invention in functional amounts without departing from the scope thereof. For example, the detergent compositions of this invention can be combined with common detergent additives such as hydrotropes, heat stabilizers, colorants, degelling agents, viscosity improvers, builders, perfumes and so forth.

It is recognized in the art that major or minor amounts of other ingredients can be added to a detergent composition without destroying their detergent properties. For example, the detergent compositions of this invention can be combined with major or minor amounts of other detergents such as alkyl benzene sulfonates without departing from the scope of this invention.

The following example is given to illustrate a specific embodiment of this invention and should not be construed as a limitation upon the scope thereof.

EXAMPLE Three basic detergent formulations containing Parts Detergent 23 Sodium salt of t-nonyl phenol poly(ethoxy)ethanol sulfate (a foam builder) 10 Diethanol amide of lauric acid (a foam builder) 5 Water 62 were prepared. The detergent in the first formulation was sodium n-hexadecanol sulfate, in the second, the detergent was a mixture of the sodium salts of branched chain C primary alcohol sulfates (67% 2-methyl and 33% 2-ethyl). The third formulation contained a mixture of the first two detergents, namely; 40 percent of the sodium n-hexadecanol sulfate and 60 percent of the sodium salts of the branched chain C alcohol sulfates. Each of the above detergents contained percent by weight sodium sulfate produced during the neutralization of the sulfonic acid.

The three detergent formulations were evaluated for dishwashing performance in the following procedure:

Seven grams of a bacon fat-egg mixture containing 40 percent by weight fat were spread on each of twenty-five dinner plates. The soiled plates were baked for minutes at 100 F. and then allowed to cool at room temperature for 30 minutes.

Three dishwashing solutions were prepared by adding 7.9 grams of each detergent formulation to 2 liters of water (180 p.p.m. hardness) at 100 F. This provided solution having a total solids content of 0.15 percent which was attributable to the detergent, sodium sulfate, and builders. Each solution was agitated for 30 seconds to generate foam. The effectiveness of the solution is determined by the number of dishes which can be washed before substantially al lof the foam disappears.

The dishwashing ability of the above detergent formulation was as follows:

Type detergent in the formulation- Number of dishes washed Sodium n-hexadecanol sulfate 3 Sodium salts of beta-branched chain C alcohol sulfates A blend of 40 percent sodium n-hexadecanol sulfate and 60 percent sodium salts of betabranched chain C alcohol sulfates 11% wherein R is a straight chain alkyl radical containing 14 to 18 carbon atoms and X is a radical selected from the group consisting of Na, K, NH RR"NH and RR"R"N wherein RR and R' are hydroxylated alkyl radicals containing from 1 t0 3 carbon atoms and (b) from to 10 parts of a beta-branched chain primary alcohol sulfate having the structural formula wherein the total number of carbon atoms ranges from 12 to 20 and R is a straight chain alkyl radical containing 9 to 17 carbon atoms and R is a straight chain alkyl radical containing 1 to 9 carbon atoms and X is as defined in (a) with (B) From 0 to 10,000 parts water and (C) From 0 to parts of foam builders.

2. A composition according to claim 1 wherein X in (a) and (b) is sodium.

3. A composition according to claim 1 wherein the beta-branched chain primary alcohol sulfate in (b) contains 14 to 18 carbon atoms.

4. A composition according to claim 1 wherein R in (b) is a methyl or ethyl radical.

5. A composition according to claim 1 wherein the concentration of beta-branched chain primary alcohol sulfate of (b) ranges from 20 to 60 parts.

6. A composition according to claim 1 wherein the primary alcohol sulfates ((a)+(b)) are combined with Water.

7. A composition according to claim 6 wherein the Water is present in amounts ranging from to 900 parts.

8. A composition according to claim 1 wherein a foam builder is present in an amount ranging from 5 to 60 parts.

9. A composition according to claim 1 wherein the foam builder is a straight chain carbon compound containing a total of from 12 to 15 carbon atoms and selected from the group consisting of carboxylic acid mono and diethanol amides and primary alcohol ethoxy sulfates and ethoxylates.

10. A composition according to claim 1 consisting essentially of:

(A) 100 parts of detergent comprising (a) 36 parts of sodium n-hexadecanol sulfate and 4 parts of sodium sulfate (b) 36 parts of Z-methyI-pentadecanol sulfate, 18 parts of Z-ethyI-tetradecanol sulfate and 6 parts of sodium sulfate with (B) 270 parts of water and (C) 44 parts of the sodium salt of t-nonyl phenol poly(ethoxy)ethanol sulfate and 22 parts of N, N-diethanol dodecanamide.

References Cited UNITED STATES PATENTS 3,338,949 8/1967 Hagemeyer et al. 260-459 MAYER WEINBLATT, Primary Examiner US. Cl. X.R 252-137, 161; 260-458 

